To beat Eternatus in Pokémon GO, it generally takes around 6 players with well-coordinated teams to defeat it, although some sources mention up to 100 players may be ideal for smoother progression in raids. Key strategies include using a combination of shields, healers, and strong damage dealers. Recommended Pokémon counters include Dynamax Latios, Dynamax Metagross, Dynamax Excadrill, Crowned Shield Zamazenta (for defense), and Chansey (for healing). Effective moves are Dragon, Ground, Psychic, and Ice types, as Eternatus is weak to those. Summary:

• Suggested minimum: about 6 players with solid teams to beat Eternatus.
• Ideal raids sometimes mention around 100 players for the event.
• Use strong DPS Pokémon (e.g., Dynamax Latios, Metagross) with shielding (Metagross) and healing (Chansey).
• Weaknesses: Dragon, Ground, Psychic, and Ice type moves.
• Avoid Bug, Grass, Water, Fire, Electric, Poison, and Fighting types as they deal less damage.

This mix of teamwork and using the right Pokémon types is the best approach to beat Eternatus in Pokémon GO raid encounters.